why your nutrition clients aren’t sustaining behaviour change and what to do about it
Despite our best efforts as nutrition professionals, many clients struggle to maintain behaviour change in a meaningful and sustained way. They may start strong with dietary and lifestyle changes, only to revert to old ways within a few weeks.
If you’re seeing this pattern in your nutritional practice, you’re not alone. And it’s very likely not a reflection of your client’s willpower or your professional skill, but of a missing layer in your clinical framework: behaviour change science.
As a trainee health psychologist specialising in eating behaviour and nutritional therapy for disordered eating, I observe a similar pattern over time: well-intentioned client recommendations and carefully curated nutritional protocols, yet a challenge when it comes to achieving long-term change. The key lies in understanding how behaviour change really works and how to apply it in a clinical nutrition setting.
the real reason nutrition clients don’t sustain change
Sustainable behaviour change isn’t just about knowing what to do. It’s about whether a client is psychologically, emotionally, and contextually able to do it consistently over time.
This is where health psychology — the science of how psychological, behavioural, and social factors influence health — comes in.
There are three evidence-based reasons why your clients may struggle to embed lasting change.
there is a focus on Information, not transformation
Clients don’t change because of nutritional education alone. They change through psychological mechanisms such as motivation, identity shifts, behavioural strategies and self-efficacy.
For example, a client might fully understand the role of blood glucose balance or digestive health, yet still default to old eating patterns. This is not a knowledge problem; it’s a behavioural one.
the role of psychological flexibility is overlooked
One of the most robust predictors of sustainable behaviour change is psychological flexibility — the ability to stay in contact with the present moment and take action aligned with values, even when it's uncomfortable.
This is the foundation of Acceptance and Commitment Therapy (ACT), a behaviour change model increasingly used in health and wellness settings, including nutritional therapy and eating disorder recovery.
Here is the reality: without tools to manage difficult emotions, intrusive thoughts or urges, clients will often abandon healthful behaviours when life gets hard.
We see this in the all-too-common “start strong, crash quickly” cycle. Integrating ACT-based strategies, such as values clarification, cognitive defusion, and acceptance enables clients to persist even when motivation is low.
there isn’t focus on identity-based change
Behaviour is driven by identity and values (i.e., what is important to that client). If a client sees themselves as someone who is “bad with food,” “lacks self-control,” or “always fails,” then even the most evidence-based interventions will eventually collide with that belief system.
Sustainable change happens when we support clients to build a new identity, not just adopt new behaviours. This is the difference between “I’m trying to eat better” and “I’m someone who values nourishment and self-care.”
Health psychology frameworks like the COM-B model and Self-Determination Theory reinforce the importance of autonomy, identity and psychological needs in creating behaviour that lasts.
so how do nutritional practitioners get better results with behaviour change techniques
If you’re ready to move beyond nutritional advice and education and into meaningful and lasting results, here are three practical, evidence-based strategies you could consider implementing:
strategy 1. values not outcomes
Begin by helping clients clarify their why. Instead of focusing on goals and outcomes, explore the deeper values driving change such as energy to be able to play with their children, or less digestive discomfort so they can be present and build meaningful relationships.
This values-based approach builds intrinsic motivation, a key predictor of long-term behaviour change.
strategy 2. teach emotional regulation, not food regulation
Help clients develop skills to navigate their inner worlds (so their thoughts, feelings and physical sensations). Techniques include:
Cognitive defusion (e.g. “I’m having the thought that….”)
Mindful awareness of internal experiences (e.g., where am I feeling anxiety in my body right now?)
Compassion-based reframing of setbacks (e.g., if I was viewing this through a lens of self-care, how could I frame this?)
These are core components of third-wave CBT approaches like ACT and compassion-focused therapy (CFT), both of which are highly relevant for nutritional practitioners.
strategy 3. assess readiness
Behaviour change requires psychological safety. This is particularly important when working with clients showing signs of disordered eating, trauma history, or chronic stress.
Use tools such as:
The Stages of Change Model to assess readiness
Motivational interviewing to evoke autonomy and promote self-efficacy and choice
Psychoeducation to normalise ambivalence and setbacks (as ‘learning events’) and as a common feature of change
And where needed, involve multidisciplinary input from counselling or mental health services to ensure ethical and effective care.
final thoughts
If your nutrition clients aren’t sustaining behaviour change, it’s not because you’re doing anything wrong, but because our profession is still catching up with what health psychology has long known: knowledge does not equal change.
Real results come when we shift from protocols to processes, from education to empowerment, and from short-term behaviour shifts to an understanding of behavioural patterns.
want to learn more?
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